1/*- 2 * Copyright (c) 2003 David Xu <davidxu@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29#include "namespace.h" 30#include <errno.h> 31#include <stdlib.h> 32#include <pthread.h> 33#include "un-namespace.h" 34#include "thr_private.h" 35 36__weak_reference(_pthread_barrier_init, pthread_barrier_init); 37__weak_reference(_pthread_barrier_wait, pthread_barrier_wait); 38__weak_reference(_pthread_barrier_destroy, pthread_barrier_destroy); 39 40int 41_pthread_barrier_destroy(pthread_barrier_t *barrier) 42{ 43 pthread_barrier_t bar; 44 int ret, ret2; 45 46 if (barrier == NULL || *barrier == NULL) 47 return (EINVAL); 48 49 bar = *barrier; 50 if (bar->b_waiters > 0) 51 return (EBUSY); 52 *barrier = NULL; 53 ret = _pthread_mutex_destroy(&bar->b_lock); 54 ret2 = _pthread_cond_destroy(&bar->b_cond); 55 free(bar); 56 return (ret ? ret : ret2); 57} 58 59int 60_pthread_barrier_init(pthread_barrier_t *barrier, 61 const pthread_barrierattr_t *attr __unused, unsigned count) 62{ 63 pthread_barrier_t bar; 64 int ret; 65 66 if (barrier == NULL || count <= 0) 67 return (EINVAL); 68 69 bar = malloc(sizeof(struct pthread_barrier)); 70 if (bar == NULL) 71 return (ENOMEM); 72 73 if ((ret = _pthread_mutex_init(&bar->b_lock, NULL)) != 0) { 74 free(bar); 75 return (ret); 76 } 77 78 if ((ret = _pthread_cond_init(&bar->b_cond, NULL)) != 0) { 79 _pthread_mutex_destroy(&bar->b_lock); 80 free(bar); 81 return (ret); 82 } 83 84 bar->b_waiters = 0; 85 bar->b_count = count; 86 bar->b_generation = 0; 87 *barrier = bar; 88 89 return (0); 90} 91 92int 93_pthread_barrier_wait(pthread_barrier_t *barrier) 94{ 95 int ret, gen; 96 pthread_barrier_t bar; 97 98 if (barrier == NULL || *barrier == NULL) 99 return (EINVAL); 100 101 bar = *barrier; 102 if ((ret = _pthread_mutex_lock(&bar->b_lock)) != 0) 103 return (ret); 104 105 if (++bar->b_waiters == bar->b_count) { 106 /* Current thread is lastest thread */ 107 bar->b_generation++; 108 bar->b_waiters = 0; 109 ret = _pthread_cond_broadcast(&bar->b_cond); 110 if (ret == 0) 111 ret = PTHREAD_BARRIER_SERIAL_THREAD; 112 } else { 113 gen = bar->b_generation; 114 do { 115 ret = _pthread_cond_wait( 116 &bar->b_cond, &bar->b_lock); 117 /* test generation to avoid bogus wakeup */ 118 } while (ret == 0 && gen == bar->b_generation); 119 } 120 _pthread_mutex_unlock(&bar->b_lock); 121 return (ret); 122} 123